Optical anisotropy is known in the art for dopes (or solutions) of synthetic polyamides, e.g., the dopes of Kwolek U.S. Pat. No. 3,671,542. Liquid crystal behavior is reported in the art for polyolefin melts.
Polyazomethines [or poly(Schiff bases)] are extensively described in the literature [e.g., in "Encyclopedia of Polymer Science and Technology", Vol. 10, 659-670 (1960), Interscience Publishers, New York, G. F. D'Alelio] and in the patent art, e.g., in U.S. Pat. Nos. 3,526,611 and 3,418,281.
Polyazomethines that can be molded at high temperature and at high pressure have been disclosed in U.S. Pat. No. 3,418,281 and British Patent No. 1,080,526. The polymers are said to have good thermal stability and toughness. Films of polyazomethines that have been cast from dilute solutions or that have been pressed at high temperatures and at high pressures are disclosed in Baker et al. T 918005, Jan. 1, 1974 Official Gazette (Defensive Publication). However, none of this prior art suggests that certain aromatic polyazomethines can form anisotropic melts which can be melt spun directly into filaments.